Process for the production of photographic materials



United States 3,liZZ,l72 Patented Feb. 20, 1262 thee 3,022,172 PROCESS FOR THE PRODUCTIQN F PHOTO- GRAPHHC MATERIALS Seiichi Ghha, Ashigaraiiami-gun, Kanagawa-ken, and

Teruhiko Yonezawa and Akira Kumai, Minamiashigarannachi, Ashigarakami-gun, Kanagawa-ken, Japan, assignors to Fuji Photo Film Co. Ltd., Ashigarakamigun, Kanagawa-ken, Japan, a corporation of Japan No Drawing. Filed May 6, 1959, Ser. No. 811,289 Claims priority, application Japan May 13, 1958 3 Ciaims. (Cl. 96-114) This invention relates to photographic materials and more particularly to photographic emulsions.

It is a well-known fact that gelatin is now widely used as a protective colloid relative to photographic emulsions. Gelatin is, however, not entirely suitable for the purpose and has some disadvantages as will be herein after described. Attempts have hitherto been made to manufacture photographic emulsions by using various synthetic substances as a full or partial substitute for gelatin. The substances which have been proposed or tried for this purpose are Water-soluble high molecular compounds such as polyvinyl alcohol, partially hydrolyzed polyvinyl esters, polyvinyl acetals, polyacrylic acids, polyacrylic amides, partially hydrolyzed cellulose esters and the like. Despite these attempts, gelatin possesses many worthy qualities by reason of which it remains the protective colloid most widely employed for photographic emulsions. It is an object of the present invention to provide synthetic materials which not only possess the advantageous properties of gelatin, but which also avoid its many disadvantages and even impart better qualities.

It is generally known that in coating a photographic emulsion on a support to a uniform desired thickness, the viscosity of the emulsion plays an important role. Therefore, when it is necessary, for example, to increase the ratio of silver halide to protective colloid, and to make a thinner emulsion layer, which still retains as good characteristics as a thicker layer, the emulsion fails to attain the required viscosity. Accordingly, the invention contemplates a substance which can be added to gelatin to increase the viscosity to its required value and at the same time to maintain the desirable photographic and other physical characteristics of the emulsion.

We have found that the objects of the invention can be obtained by adding to a photographic emulsion a recurring interlinear homopolymer which is composed of a sole unit selected from the group of units represented by the formulae:

-CHz-CH CHz-(|3H CHz-(|7H on,

SOgX R sioax so x (wherein X is a radical selected from the group consisting of hydrogen, ammonium and alkali metals; and R is an alkyl group containing 1 to 4 carbon atoms).

Monomers used for producing the water-soluble polymers for the present invention include potassium vinylsulfonate cH,:cHso,K potassium allylsulfonate (CH :CHCH SO K), sodium allylsulfonate (CH CHCH SO Na) sodium p-vinylb enzenesulfonate OHHCE-QsmNQ potassium 2-methyl-4-vinylbenzenesulfonate (CHKOH 303K) 0 H; sodium-Z-methylA-vinylbenzenesulfonate (CHztCH SO NB) and the like.

The polymer according to the present invention is miscible with aqueous gelatin solution in any proportion. A mixture of gelatin and the polymer of the present invention provides a protective colloid for silver halide and has properties of thermal-reversible change between sol and gel, and also of fast adhesion to a support such as paper, glass and high molecular substance. The emulsion layer applied and dried has good water-permeability, so that it causes no hindrance to the so-called photographic treatments, namely, development, fixing, etc.

Various water-soluble, high molecular compounds heretofore suggested have defects when added to a photographic emulsion. On the contrary, the synthesized substances to be used in the process of the present invention have no subsidiary undesirable effects, and the addition of these substances does not affect the convertability of the photographic emulsion between sol and gel, the protecting of crystals of silver halide, the water permeability, the physical strength of the emulsion layer and other photographic characteristics such as sensitivity, gamma and fog.

Furthermore, said synthesized substances to be used in the process of the present invention can advantageously be manufactured less expensively in comparison with gelatin and can be conveniently supplied, used and stored, since there is no fear of decomposition and deterioration. It is ditiicult to obtain gelatin of constant quality independent of the associated raw materials such as animal bone, skin and the like, and the related manufacturing technique. On the contrary, the synthesized substances according to the present invention can be produced with invariable quality, and can be stored and supplied without difi iculty.

The substances of the invention can be used regardless of the composition and the kind of silver halide, the form of chemical sensitizer, the presence or absence of optical sensitizer and the kind of support.

The process for producing photosensitive materials according to the present invention is characterized by adding to a photographic emulsion a homopolymer composed of recurring units having said structure, at any stage in the manufacture of sensitive silver halide emulsion layer. Said polymer can be added in any proportion to the amount of dry gelatin contained in the sensitive emulsion, but the addition of 0.0230% by weight of the derivative is preferred.

EXAMPLE 1 The production of poly-vinylsulfonic acid and the use thereof parts of distilled water was heated at 90 tion was completed after 4 hours. product thus obtained was purified by precipitating the concentrated. The concentrate was dissolved in acetic bath and 1,2-ethanesulfonic chloride was obtained. The chloride obtained from 200 g. of sodium salt weighed A solution of 1 part of the chloride in 10 parts of water was heated until gaseous hydrochloric acid disappeared, and then distilled under reduced pressure to obtain vinylsulfonic acid.

A solutionof 1 part of the monomeric acid'in 20 C. with 0.01 part of potassium persulfate as a catalyst. Polymeriza- The polymerization same with methanol, and the product was then dried.

Five grams of this polymer were completely dissolved at room temperature in 200 ml. of distilled water, and the solution was added to a solution of 5 g. potassium iodide, 165 g. potassium bromide and 65 g. gelatin dissolved in 1500 ml. of distilled water and the resulting solution was heated at 70 C. Into this mixture, 2000 ml. of an aqueous solution of silver nitrate heated up to 72 C. were poured with accompanying stirring during a period of about 10 minutes and'therea'r'ter the mixture was digested at 70 C. for minutes. The mixture had further added thereto 250 g. of gelatin and the resulting product was digested again at the same temperature for 20 minutes and then gelated by quick cooling; The gel was cut into small cubes of about 1 cm. and washed in water at about 10 C. for several hours to remove water-soluble salts from the gel. The photo-sensitive emulsion thus prepared was melted at 60 C. and hereto 100 g. of gelatin were added together with proper quantities, as required, of Sulfur sensitizers, reduction sensitizers, gold sensitizers and the like, and further ripened for about minutes (the so-called 2nd ripening). To this emulsion, optical sensitizers, stabilizers, hardening agents and surface active agents may be added, ifneed be. The emulsion was coated on a film base to athickness of about 20 microns.

The emulsion prepared according to a light-sensitive emulsion prepared in the same way with out the addition of said polymerization product, but was also superior in viscosity.

The following table shows the photographic characteristics and the relative viscosity at C. as measured on the basis of JIS-K-7064.

The production of poly-sodium-vinylsulfonate and the use thereof 1 part of sodium monobromomethane sulfonate and 1 part of caustic .sodawere dissolved in 10 parts of water and allowed to stand at room temperature for a day and acid and. extracted with ether to obtain sodium vinylsulfonate. One part of the monomeric sulfonate was dissolved in 2 parts of distilled water and then polymerized with 0.01 part of potassium persulfate. The solution was heated to 90 C., the reaction was over within about five hours. cipitated by pouring the reaction mixture into methanol. The precipitate was washed two or three times with methanol, and dried.

The polymer thus prepared was used for a sensitive, emulsion as described in the following:

FORMULA I A Potassium bromi g 165 Potassium iod g 5 Gelatin g-.. Poly-sodium-vinylsulfonate g 5 Distilled water ml 1700 B Silver nitrate g 200 Distilled water ml 1800 C Gelatin g .250 FORMULA II A Potassium bromide g 165 Potassium iodide g 5 Gelatin g 65 Distilled water ml 1700 B Silver nitra e g 200 Distilled water--- ml 1700 C Gelatin g 350 The solution A above was kept at C. and into the same was poured the solution B at 72 C. during a period of about ten minutes with stirring. The mixture was maintained at 70 C. and digested for twenty minutes, and gelatin C above was added and the mixture was further digested for another 20 minutes. The sensitive emulsion thus prepared was cooled quickly, washed,

' and the second ripening effected in the same way as men- 7 this invention was 7 not only comparable in sensitivity, fog and gradation to tioned in Example 1.

. As compared with the sensitive emulsion prepared according to Formula 'II, the emulsion of Formula I is short of gelatin by grams. There is however almost no difference between thetwo emulsions in relative vis- 7 cosity, sensitivity, gamma and fog as shown below:

7 dried, the emulsion above Polymeric sulfonate was pre- Sensitivity Gamma Fog Viscosity Emulsion]: 0.68 0. 04 15.9 Emulsion II 180 0. e2 0. 04 16.5

EXAMPLE 3 The production of polyvinylsulfonamide and the use thereof To 1 part'of ethane disulfonic chloride dissolved in 5 parts of benzene, 2 parts of liquid ammonia were added under cooling. After the separated hydrochloride was removed and benzene was distilled out, vinylsulfonamide was obtained. The polymerization was carried out in the same manner as shown in Example'l ,to obtain polyvinylsulfonamide. 7

Twenty percent aqueous solution of the purified polymerization product was added to a gelatin-silver chlorobromide emulsion for enlarging paper at the rate of 15 ml. per 1 kg. of emulsion just before its application. The viscosity of the emulsion was raised.

When an emulsion was coated on baraytaged paper and mentioned was by no means inferior to an emulsion without the polymer in the initial image at development, sensitivity, gradation and tone of EXAMPLE 4 The production of potassium poly-p-izjnylbenzenesulfonate and theme thereof To 5 partsof chlorosulfonic acid castes to 10? c.

was slowly added 1 part of (,B-bromoethyl) benzene. After the reaction was over, the reaction mixture was poured into chopped ice with vigorous stirring. This mixture was extracted with ether. Then the ether extract was washed with water and dilute sodium bicarbonate solution. The ether was removed under vacuum leaving the crude sulfonyl chloride. This chloride was added to 10 parts of methanol. The solution was cooled with an ice-bath, while 10 parts of methanol containing 4 parts of potassium hydroxide were added. After refluxing for 1 hour, the mixture was cooled. Potassium bromide and potassium chloride, both by-products, were removed to obtain potassium p-vinylbenzenesulfonate. The polymer was produced in the same manner as described in Exampie 1.

To a gelatin-iodobromide photographic emulsion for high-sensitive negative films prepared by the known method were added 20 ml. of 5% aqueous solution of said polymerization product and coated on a film base. The film thus produced is a high-sensitive negative film having characteristics good for practical use.

EXAMPLE 5 A solution of 26 g. of potassium chloride, 7 g. of potassium bromide and 8 g. of gelatin in 230 ml. of distilled water was maintained at 45 C., whereto a solution of 50 g. silver nitrate in 920 cc. distilled water was added in 15 minutes under stirring, the temperature being kept at 42 C. After the adding of 100 g. of gelatin, the solution was further stirred for 15 minutes, then cooled with ice, and thereafter there were added 5 g. of poly sodium vinylsulfonate and distilled water, thus to make a total of 2000 g., and the solution was ripened at 55 C. for 100 minutes.

To the sensitive emulsion thus obtained, there were added under stirring at 30 C., 20 parts of a 0.05% methanolic solution of 3-allyl-3-ethyl-5-(2-(l-ethyl-4- quinolinilidene)ethylidene) 5',6' dimethyl-4- oxothiazolino-oxacyanin iodide and 2000 parts of a 5% alkaline solution of N-octadecyl-l-hydroxy-4-sulfo-2-naphthamide, and then the mixture was coated on a film base and dried, to produce a thin photographic emulsion layer.

Similarly, to said ripened emulsion were added 20 parts of a 0.05% methanolic solution of 3,3,9-triethyloxacarbocyanin iodide and 2000 parts of 5% alkaline solution of S-heptadecyl-l-(4-phenoxy-3 sulfophenyl)-2-pyrazolin-5- one, and then the resulting above mentioned layer.

product was coated onto the Further, to said ripened emulsion were added 2000 parts of a 5% alkaline solution of 5-(4-stearoamidebenzoylacetamidofisophthalic acid to obtain a product which was applied as the uppermost layer.

The color positive film thus coated and dried has no undesirable sensitivity hitherto known color resolving power.

We claim:

positive and color tone as compared with film and has an improved 1. A photographic silver halide gelatin emulsion containing a linear homopolymer selected from the group of homopolymers consisting of recurring units represented by the formulae:

wherein X is a radical selected of hydrogen, ammonium and alkyl group containing 1 to 4 of said homopolymer being 0.

from the group consisting alkali metals; and R is an carbon atoms, the amount 02-30% by weight on the Minsk Aug. 21, 1956 FOREIGN PATENTS Germany June 3, 1954 OTHER REFERENCES Wiley et al.: J. Am. Chem. 5, 1954, p. 720.

Soc., 76, No. 3, February 

1. A PHOTOGRAPHIC SILVER HALIDE GELATIN EMULSION CONTAINING A LINEAR HOMOPOLYMER SELECTED FORM THE GROUP OF HOMOPOLUMERS CONSISTING OF RECURRING UNITS REPRESENTED BY THE FORMULAE: 